In 2001, Dr. Richard Wiseman asked a
question: what is the world’s funniest joke? He got people to submit and rate
jokes on his website, LaughLab. After 40,000 submissions and one million ratings, he got
his answer. Are you ready for the world’s funniest joke, as determined by science? Here it is.
Two hunters are out in the woods when one of them collapses. He doesn’t seem to be breathing
and his eyes are glazed. The other guy whips out his phone and calls the emergency services. He
gasps: “My friend is dead! What can I do?” The operator says: “Calm down, I can help. First,
let’s make sure he’s dead.” There is a silence, then a gunshot is heard. Back on the
phone, the guy says: “Okay, now what?” Now whether or not you thought that joke was
funny, it raises some interesting scientific questions. Why did so many people find it
amusing? What makes a good joke? What is humor? Why do we laugh at all? These
are actually complicated questions, and there are multiple hypotheses as to what humor
is and why we laugh. Let’s spend a little time exploring what exactly tickles our funny bone.
One strategy for studying humor is to start by finding out what exactly makes us laugh.
Laughter is ubiquitous. A good estimate says that we laugh about 17 times a day. It’s
a pleasurable activity that makes us feel good. We even have entire industries built
around making us laugh. If you’ve ever gone to a stand-up comedy show or watched a comedy
movie, you’ve participated in these industries. Biologically, laughter is a human universal
that starts around 3.5 to 4 months of age. It’s an automatic reaction to amusing stimuli,
or tickling. Mechanistically, it’s a series of staccato segments that are each about 1/15 of
a second, separated by about 1/5 of a second. Laughter is usually full of vowels as well:
hence the familiar “ha-ha” or “ho-ho.” What about the physiological or neural components
behind laughing? When you laugh, 15 different facial muscles contract. Your zygomaticus major,
the main muscle responsible for lifting your upper lip, is also stimulated. In your respiratory
system, the larynx, or top of your windpipe, is half-closed by the epiglottis, a flap of cartilage
that usually covers your windpipe when swallowing to keep you from choking. This half-closure makes
air intake happen irregularly, making you gasp. In extreme circumstances when you are laughing
a lot, your tear ducts are also activated. Research from Peter Derks tells us what happens
in your brain when you laugh at a joke. First, the left side of your cortex, the side that is
generally responsible for language and speech, analyzes the words and structure of the joke.
Your frontal lobe then becomes very active. The right hemisphere of your cortex will also show
activity, presumably the intellectual analysis required to “get” the joke. Brainwave activity
then spreads to the sensory processing area of the occipital lobe, the area in the back of
the brain that processes visual signals. If the motor cortex is stimulated, there will
also be physical responses to the joke. Laughter itself appears to come from a
specific area of the brain. One study in 1998 traced it to a small, 2 cm by 2 cm area on
the left superior frontal gyrus. In this study, electrical stimulation was applied to 85 different
sites on the brain of a girl who had serious seizures in an effort to figure out where the
seizures were coming from. When this small area was stimulated, the girl consistently produced
laughter and felt a sensation of merriment or mirth. At the very least, this area of the
brain is extremely important for laughter. Finally, laughter also appears to be rewarding
physiologically. It seems to be regulated by the same reward-circuit that makes us feel
good when we perform activities. Endorphins, the same chemicals that can give you a “runner’s
high” are also released during laughter. In fact, there is an ounce of truth to the saying “laughter
is the best medicine”. It reduces stress hormones, decreases muscle tension, and increases positive
immune markers. In diabetics, laughter can lead to less of an increase in blood sugar after a meal.
And of course, laughter is incompatible with many chronic negative emotional states that are bad
for one’s health, like anger and depression. It’s hard to be angry and laugh at the same time.
All of this explains mechanistically how we laugh. But when do we laugh and why? Laughter seems
to be a social and communicative activity. We rarely laugh alone. In fact, people are
30 times more likely to laugh in a social setting. Laughter may actually aid in social
bonding, helping bring us closer together. Dr. Robert Provine conducted years of naturalistic
studies that provide evidence for this. He and his research assistants went to malls and city
sidewalks to record what happened just before people laughed. Over 10 years they studied over
2,000 cases of naturally occurring laughter. What did they find? First, women tend to laugh more
than men, unless men are listening to a woman. They also found that the talker laughs 50% more
than the listener in a conversation. Most laughter also doesn’t follow jokes, or any real attempt at
humor. 90% of pre-laugh comments were things like, “I’ll see you guys later,” “Are you sure?”, “I
know!”, and “Does anyone have a rubber band?” These comments are obviously not funny. This
suggests that laughter can instead serve as a way to create social bonds between people.
But what about humor itself? Why are things funny? We actually don’t know for sure.
Psychologists are still trying to figure out what aspects of a joke or situation make us
laugh. We do, however, have various theories. One theory is that humor is due to incongruity.
We laugh when there is a disconnect between what we expect and what actually happens.
Punchlines from incongruent jokes force us to reconsider or reframe something. Take this
joke. Police were called to a daycare center, where a three-year-old was resisting a rest. When
we hear the beginning of the joke about police, we don’t expect the punchline to be about a child
not wanting to take a nap. But incongruity isn’t the best explanation for humor, especially since
there are many cases when incongruity doesn’t cause laughter at all. Would you laugh if you got
an F on a test when you thought you got an A? No, because that isn’t funny, even though there is a
disconnect between our expectations and reality. Another possible explanation for humor is the
theory of superiority. We laugh at earlier versions of ourselves and the misfortunes
of others because we think we are better than them. This type of humor is usually used to
ridicule others. Think back to your childhood, playing on the playground or being in school.
Did you ever laugh when someone dropped their lunch or passed gas? Your laughter could
be explained by the realization that you are superior to that poor person. Here’s
another example: It’s pretty funny if the Queen of England farts because it goes against
the regality and majesty we expect from her. Psychologists Thomas Veatch and Peter McGraw
propose yet another theory: humor arises from a benign violation of an accepted rule or
moral. Emphasis on benign here; jokes with this type of humor only work if the violation
is non-threatening. In this case, an ethical, social, or physical norm has been violated, but
the violation isn’t very offensive or upsetting. This theory helps explain slapstick humor. We
know that being hit in the head with a frying pan causes brain damage. But when the Three Stooges
do it, we laugh because we know it’s just cartoon violence and the characters aren’t actually hurt.
Humor could also just be the result of a release of tension. The philosopher John Morreall
suggested that laughter may have its biological origins as a kind of shared expression
of relief at the passing of danger. We laugh when something builds up tension and then relieves
it. Sigmund Freud would agree. In his view, laugher lets people release pent-up “nervous
energy.” This explains why we laugh at poop jokes and jokes about sex. When we reach the
punchline, we don’t have to keep suppressing supposedly inappropriate emotions like desire
or disgust. This energy is released as laughter. Finally, we may be able to explain parts of
humor in an evolutionary context. Laughter and humor occur in every human society. While
we’re the only species to give out loud guffaws in response to a joke, some animals seem to
make laughter-like sounds when they play. Rats, for example, will chirp while they play in a way
that resembles our giggles. When rats are tickled, they also chirp and socially bond with their human
tickler. And rats seem to like being tickled; they actively seek more tickling. Non-human
primates also seem to laugh. When chimps play, tickle, and chase each other, they produce a sound
similar to human laughter. The universality of laughter even outside of humans suggests that it
could play an evolutionary role. For instance, laughter could be important for animals and for
our ancestors in signaling when mock aggression and play fights are just that, a form of play.
If you’re laughing as you wrestle with someone, you make it clear that you’re just playing
and not actively trying to harm them. Humor is complicated. Although we have
a lot of theories about why we laugh, we honestly don’t really know precisely what makes things funny. But maybe we don’t have to.
Maybe some jokes are best left unanalyzed.
